Casing-coupling.



J. A. MASON.

CASING COUPLING.

APPLICATION FILED APR. 10. 1914.

Patented J une 1, 1915.

Q IF IT!!! L u E I 4 n T m INVENTDR ATTURNEY.

JESSE A. MASON, OF MANININGTON, WEST VIRGINIA.-

i i CASING-COUPLING.

LIdLQlO.

To all whom it may concern Be it known that I, Jesse A. Mason, a citizenof the United States of America, and resident of Mannington, countyofMarion, and State of \Vest Virginia, have invented certain new anduseful Improvements in Casing-Couplings, of which the following is aspecification.

This invention relates to couplings designed for use in connection withwell casing or tubing, and it has for its primary object to provide acoupling for deep-Well casing which will permit of the ready removal orwithdrawal of such casing from the well.

Hitherto the couplings universally used have been formed with awell-defined, or pronounced, external annular inwardlydirected bevel orrounded shoulder at each ofits ends. Due to this beveled or roundedshoulder, much trouble is experienced in withdrawing the casing, andmany millions of feet of the latter are yearly left in abandoned oil andgas wells because of inability to withdraw it. The cause of theditliculty will be realized when it is understood that earth caves inand settles close around the casing at occasional points throughout thedepth of the well, and that. to withdraw the string of easing, thecouplings, which have a diameter greater than that of the casing, mustbe drawn through the casing-embracing earth, displacing the latter. Inelevating the string of casing the beveled or .rounded upper end of thecouplings acts to exert upon the embracing earth a wedging pressurewhich forces said earth outward and upward, the line of force exerted bysuch coupling upon said earth being at substantially an angle of degreesto the axis of the well. As the string is elevated, the resistanceoffered by the embracing earth I constantly increases, due to the factthat said earth is constantly becoming more compact with the elevationof the coupling thereagainst; With such resistance, added to the greatsuspended weight of a long string of casing, it frequently happens that,after an elevation of a few feet, it isutterly impossible to applysufficient power to ac complish a further elevation. In like manner thelower end of the coupling acts to prevent the casing from being lowered.Thus, the casing becomes stuck fast in the hole and must be abandoned,ofttimes resulting in a great financial loss. Furthermore,

Specification of Letters Iatent.

Application filed April 10, 1914. sea-1&1 No. 831,059.

Patented June I, 1915.

the use of the common form of coupling frequently results in thespreading and consequent breakage of the elevators employed in elevatingthe casing. This is due to the fact that the lower beveled or roundedend of the coupling engaged by the clamp members of the tool exerts,under the stress imposed by the great weight of the suspended casing,even under the most favorable elevating conditions, a wedging force uponsaid members which tends to spread the.

latter in a manner well understood by those skilled in the art.

It is the object of the present invention, therefore, to obviate thedifliculties above noted, and this is attained by the provision of acoupling of an extremely simple and inexpensive form, the nature ofwhich will hereinafter be fully explained. reference being had to theaccompanying drawings, forming a part of this specification, in which-Figure 1 is a sectional view of a well,-

showing in side elevation, a string of casing disposed therein, thecasing sections being connected by means of my improved .coupling, andshowing the earth from the walls of the well closing the space aroundthe casing; and Fig. 2 is an enlarged sectional view of the couplingapplied to two adjacent casing sections.

Referring to said drawings, in which like designating charactersdistinguish like parts throughout the several views'1 indicates thesections of a noil or gas well casing which have their ends threadedexteriorlv, as ordinarily, and 2 indicates the interiorly threadedsleeve-like body of my improved coupling, the same being of uniformexterior diameter from end to end and presenting clean outcircumferential end surfaces 3 which are disposed at right angles to theaxis of the body 2.

Casing the sections of which are connected by means of my couplings maybe readily withdrawn from the well, the squared ends of the couplingsreadily cutting their way upward through, and thus clearing thecoupling, of obstructions instead of forcing the latter outward. Thereis no tendency, therefore, to force or wedge the earth in an upward andoutward direction until the latter becomes so compact as to resistfurtherelevation, as is the case when the above-mentioned common form ofcoupling is employed. ,In practice, a cutting edge is presented at thecircumferential angle 4 which, when the casing is being elevated, cutsdirectly through, and does not tend to wedgingly compact, earth whichlies-in embracing relation to the casing. Furthermore, the plainshoulder presented by the lower end of the coupling affords a positiveseat for the clamp members 5 of the elevator employed for elevating thecasing. Thus the tendency to wedgingly spread said clamp members apart,encountered in the use of the common form of coupling, as hereinbeforeexplained, is Wholly obviated. This is an important feature, since, inaddition to the breakage of elevators resulting from the spreading ofthe clamp members when the common form of coupling 'is used, itfrequently happens, in lowering easing into a well, that, due to thegreat weight of sus pended casing, the clamp members are spread apart bythe coupling to an extent that the lower body portion of the couplingwedges down between said members where it partially collapses under theexcessive gripping force. When the coupling is thus distorted orcollapsed it is difiicult, if not wholly impossible, to introduce thenext joint, or casing section, within the coupling.

lVhile the change from the common form of coupling to the improved formconstituting the present invention might appear slight to those notskilled in the art. such change results in the production of a devicewhich permits of the recovery of casing which, with the preexistingform, has been wholly iriecoverable and which, in the oil and gas fieldsof the United States, totals annually many millions of feet.

lVhat is claimed is,

The combination with the adjacent exteriorly threaded ends ofwell-casing sections, of a coupling therefor comprising an interiorlythreaded sleeve-like body the exterior diameter of which is uniformthroughout and greater than that of said sections, each end of said bodypresenting a plane circumferential surface disposed at right angles tothe axis and constituting a projecting earth cutting shoulder.

In testimony whereof, I aifix my signature in presence of twosubscribing witnesses.

JESSE A. MASON.

'Witnesses:

CHAS. V. ToBEN, GEO. A. CooHRANa.

